Borosilicate molecular sieve

Abstract

 A new crystalline borosilicate molecular sieve, boronaaronate, having a composition in terms of mole ratios of oxides:
    0.9±0.2M_2/nO:B₂O₃:ySiO₂:zH₂O
wherein M is a cation of valence n, y is between 2 and about 700, and z is between 0 and about 200, and having a characteristic X-ray diffraction pattern. The boronaaro­nate is prepared by reacting under crystallization condi­tions, in substantial absence of a metal hydroxide, an aqueous mixture containing an oxide of silicon, an oxide of boron, ethylenediamine, and an organic material com­prised of a heterocyclic nitrogen-containing aromatic compound or an aliphatic alcohol. Boronaaronate is useful in hydrocarbon conversion processes.

Description

[0001] This invention relates to a crystalline borosilicate molecular sieve having a crystalline topology similar to ferrierite aluminosilicate. The crystalline borosilicate molecular sieve is prepared by reacting under crystalli­zation conditions, in substantial absence of a metal hydroxide, an aqueous mixture containing an oxide of silicon, an oxide of boron, ethylenediamine, and a heter­ocyclic nitrogen-containing aromatic compound or an alip­hatic alcohol.

[0002] Some zeolitic materials, both natural and synthetic, are known to have catalytic capabilities for many hydro­carbon processes. Zeolitic materials typically are ordered porous crystalline aluminosilicates having a definite structure with cavities interconnected by chan­nels. The cavities and channels throughout the crystal­line material generally are uniform in size which some­times permits selective separation of hydrocarbons. Consequently, these materials, in many instances, are known in the art as "molecular sieves" and are used, in addition to selective adsorptive processes, for certain catalytic properties. The catalytic properties of these materials are affected to some extent by the size of the molecules which selectively penetrate the crystal struc­ture, presumably to contact active catalytic sites within the ordered structure of these materials.

[0003] Generally, the term "molecular sieve" includes a wide variety of both natural and synthetic positive-ion-­containing crystalline zeolite materials. They generally are characterized as crystalline aluminosilicates which comprise networks of SiO₄ and AlO₄ tetrahedra in which silicon and aluminum atoms are cross-linked by sharing of oxygen atoms. Negative framework charge resulting from substitution of an aluminum atom for a silicon atom is balanced by positive ions, for example, alkali-metal or alkaline-earth-metal cations, ammonium ions, or hydrogen alkaline-earth-metal cations, ammonium ions, or hydrogen ions.

[0004] Molecular sieves characterized as "ferrierite" by chemical composition and X-ray spectrum are known as naturally occurring materials and as synthesized mater­ials. A ferrierite sieve is characterized as a crystal­line aluminosilicate typically having a silica/alumina molar ratio of 2 to 40 and having a distinctive X-ray pattern.

[0005] A conventional ferrierite sieve is produced by crys­tallizing a basic mixture of sodium aluminate and an oxide of silicon without the use of an organic template compound. Such ferrierites are described in D. W. Breck "Zeolite Molecular Sieves," John Wiley & Sons, l974, incorporated by reference herein. U.S. Patent No. 4,000,248 discloses a method of producing a ferrierite molecular sieve using N-methyl pyridinium hydroxide as an organic template compound in the crystallization of the sieve. U.S. Patent Nos. 4,0l6,245, 4,l07,l95, and 4,046,859 disclose the formation of a ferrierite-like material using an organic template derived from ethylene­diamine, pyrrolidine or butanediamine, or organometallic 2-(hydroxyalkyl)- trialkylaluminum compounds.

[0006] U.S. Patent No. 4,25l,499 discloses the preparation of synthetic ferrierite in the presence of piperidine or an alkyl-substituted piperidine. The reference specifi­cally states that when other heterocyclic compounds such as pyridine are used "either no ferrierite at all is formed, or the ferrierite obtained is highly contaminated with other zeolitic and/or amorphous material." U.S. Patent No. 4,377,502 discloses the use of oxygen-con­taining organic templates such as ethers and hydroxy amines in the preparation of aluminosilicate ferrierite molecular sieves.

[0007] Boron is not considered a replacement for aluminum or silicon in a zeolitic composition. Although over a hundred aluminosilicate zeolites are listed by Breck, the text states that "actual incorporation of boron in a zeolite structure has not been achieved." However, a new crystalline borosilicate molecular sieve AMS-lB was dis­closed in U.S. Patent Nos. 4,268,420 and 4,269,8l3, incorporated by reference herein. According to these patents AMS-lB can be synthesized by crystallizing a source of an oxide of silicon, an oxide of boron, an oxide of sodium, and an organic template compound such as a tetra-n-propylammonium salt. In order to form a cata­lytically-active species of AMS-lB, sodium ion typically is removed by one or more exchanges with ammonium ion followed by calcination. Other methods to produce boro­silicate molecular sieves include formation of a borosi­licate using ethylenediamine with sodium hydroxide disclosed in British Patent Application No. 2,024,790. Despite discoveries of borosilicates with crystalline structures, the formation of crstalline borosilicates remains unpredictable. The reaction mechanisms whereby reaction gels are converted into crystalline borosili­cates are not sufficiently well known to suggest to one skilled in the art the reaction compositions and formula­tion techniques which could reasonably be expected to yield a crystalline borosilicate with an X-ray diffrac­tion pattern similar to that of ferrierite.

[0008] The material of this invention is referred to as "boronaaronate", a crystalline borosilicate molecular sieve having a characteristic structure as shown by its X-ray diffraction pattern and composition. Although the X-ray diffraction pattern of the boronaaronate of this invention shows similarities to that of ferrierite alumi­nosilicate zeolite, which indicates a similar crystalline topology, there are substantive differences between the respective patterns which reflect incorporation of boron into the crystalline framework of the boronaaronate molecular sieve. For example, it is known that the boron-oxygen bond length is shorter than either the sili­con-oxygen or aluminum-oxygen length. Thus, a contrac­ tion of the crystalline unit cell is expected in a molecular sieve in which boron is incorporated into the framework. Such effect on the unit cell is observed by shifts of lines in the X-ray diffraction pattern of a borosilicate as compared to an aluminosilicate. However, the crystalline boronaaronate of this invention is pre­pared in substantial absence of aluminum and consequently there may be very little aluminum present in the boronaa­ronate of this invention. The structure of boronaaronate is distinct from the structures of known crystalline borosilicates.

[0009] The object of this invention is to provide a crys­talline borosilicate-type material, boronaaronate, having a crystalline topology similar to the topology of fer­rierite. Another object of this invention is a method of producing boronaaronate, said method comprising reacting an oxide of silicon, an oxide of boron, ethylenediamine, a heterocyclic nitrogen-containing aromatic compound or an aliphatic alcohol, and water under crystallization conditions. A further object of this invention is a method of hydrocarbon conversion using the boronaaronate described in this invention.

SUMMARY OF THE INVENTION

[0010] Boronaaronate, a crystalline borosilicate having a crystalline topology similar to the topology of fer­rierite, has been discovered having the following compo­sition in terms of mole ratios of oxides:
    0.9±0.2M_2/nO:B₂O₃:ySiO₂:zH₂O
wherein M is at least one cation with the valence of n, y is between about 2 and about 700 or more, preferably between about 5 and about l50, and z is between 0 and about 200, preferably between 0 and l20, having an X-ray diffraction pattern substantially as shown in Table I.

[0011] This novel molecular sieve is prepared by a method which comprises reacting under crystallization condi­tions, an aqueous mixture containing an oxide of boron, a heterocyclic nitrogen-containing aromatic compound or an aliphatic alcohol, ethylenediamine, and an oxide of silicon. The crystalline boronaaronates of this inven­tion are particularly useful in hydrocarbon conversion processes.

DESCRIPTION OF THE INVENTION

[0012] The boronaaronate of this invention is a new crys­talline borosilicate molecular sieve material having the following composition in terms of mole ratios of oxides:
    0.9±0.2M_2/nO:B₂O₃:ySiO₂:zH₂O
wherein M is at least one cation of valence n, y is between about 2 and about 700 or more, preferably between about 5 and about l50, and z is between 0 and about 200, preferably between 0 and l20, having a low alumina con­tent and having an X-ray diffraction pattern substan­tially as shown in Table I. M is preferably hydrogen.

[0013] Boronaaronate preparations of this invention showing particular catalytic properties have a silica/boria mole ratio of about l5 to about 50.

[0014] Another aspect of this invention relates to a method of producing a crystalline boronaaronate by reacting an oxide of boron, an oxide of silicon, ethylenediamine, a heterocyclic nitrogen-containing aromatic compound or an aliphatic alcohol, and water under crystallization conditions. The crystal­line boronaaronates of this invention are useful in hydrocarbon conversion processes and are particularly suitable for isomerization of alkylaromatics such as xylenes.

[0015] A typical X-ray diffraction pattern of a boronaaro­nate molecular sieve of this invention is shown in Table I.

[0016] The boronaaronate molecular sieve of this invention is prepared by reacting, under crystallization condi­tions, an aqueous mixture containing an oxide of silicon, an oxide of boron, ethylenediamine, and a heterocyclic nitrogen-containing aromatic compound or an aliphatic alcohol.

[0017] Examples of oxides of boron are H₃BO₃, B₂O₃, and H₃B₃O₆. Examples of oxides of silicon are silicic acid, sodium silicate, tetraalkyl silicates, and "LUDOX" mater­ials (stabilized polymers of silicic acid [40% solids] manufactured by E.I. du Pont de Nemours & Co.) which include Ludox HS-40 (sodium stabilized) and Ludox AS-40 (ammonia stabilized). Another example is Nalco 2327, an ammonia stabilized colloidal silica [40% solids] manufac­tured by Nalco Chemical Company.

[0018] In addition to ethylenediamine, other organic materials used in this invention include materials such as heterocyclic nitrogen-containing aromatic compounds and aliphatic alcohols or combinations thereof. Typi­cally, suitable nitrogen-containing heterocyclic aromatic compounds contain about 4 to about 9 carbon atoms and at least one nitrogen atom in an aromatic nucleus together with their aryl- and alkyl-substituted derivatives. Examples of the aromatic compounds useful in this inven­tion include pyridine, quinoline, isoquinoline, and pyr­role. Suitable pyridine compounds include pyridine and aryl- or alkyl-substituted pyridines. Pyridine, quino­line, and isoquinoline are the preferred heterocyclic compounds in this invention. Aliphatic alcohols useful in this invention include mono and polyhydroxy alcohols and mixtures of said alcohols. Examples of suitable alcohols include C₁ - C₁₀ alkyl alcohols such as ethanol, propanol, isopropyl alcohol, and butanol or mixtures thereof. Examples of suitable alkylene glycols include ethylene glycol and propylene glycol. Preferred alcohols include ethanol, propanol, and isopropyl alcohol. Ethy­lene glycol is the preferred glycol. Substitution of other organic compounds such as alkylammonium compounds for the alcohols or aromatic compounds in this invention results in amorphous products or products with distinctly different X-ray diffraction patterns, e.g., AMS-lB crys­talline borosilicate molecular sieve.

[0019] Preferably, the boronaaronate of this invention is prepared in the substantial absence of alkali or alkaline earth metals or ions; i.e., no alkali or alkaline earth metals or compounds are added during the preparation of the boronaaronate. Although alkali or alkaline earth ions can be present as impurities in the starting mater­ials, it is advantageous that the starting reagents con­tain as little alkali metal ion contaminant as practi­cable. When sodium hydroxide was used instead of ethylenediamine in the process of this invention, an amorphous product resulted. Because ethylenediamine is used as the base, the crystalline borosilicate of this invention requires no ion-exchange procedure before for­mulation into a catalytic composition. However, if an alkali metal cation is desired, it can be placed in the boronaaronate by ion exchange after it is formed.

[0020] The mole ratios of the various reactants can be varied considerably to produce the boronaaronates of this invention. Generally in preparations according to this invention, the mole ratio of silica source to boria source may range from about l to about l50; the mole ratio of water to silica may range from about l to about l00 or higher, the mole ratio of ethylenediamine to silica may range from about 0.05 to about 5 or higher, and the mole ratio of a suitable aromatic compound or alcohol to silica may range from about 0.l to about l0 or higher. Typically, preferred mole ratios of the initial reactant concentrations for producing boronaaronate can vary as indicated in Table II:

[0021] It is possible to vary the SiO₂/B₂O₃ molar ratio in the final product in a range of about 2 to about 700, preferably about 4 to about 300, and most preferably about 5 to about l50 or more by varying the quantity of the boron-containing reactant in the reaction mixture. A molar excess of boria to silica typically is needed to produce a sieve with a particular boron content.

[0022] The molecular sieves of this invention typically have a high SiO₂/Al₂O₃ ratio which can range to over 3000:l, typically from about l000:l to about 3000:l. The typical ratio for boronaaronate is much higher than SiO₂/Al₂O₃ ratios found in the prior art synthetic fer­rierite materials and is generally limited only by the availability of aluminum-free raw materials. Because of their high SiO₂/Al₂O₃ ratios, boronaaronates are expected to have superior stability characteristics over the prior art ferrierites and to exhibit more hydrophobic surface selectivity.

[0023] In another aspect of this invention, molecular sieves with topologies similar to that of ferrierite but having lower aluminum content (higher SiO₂/Al₂O₃ ratios) than prior art synthetic ferrierites can be prepared by controlling the amount of aluminum (relative to the amount of boron) present in the starting materials and mixture. Through careful control of the aluminum content in the starting mixture, ferrierite-like molecular sieves with silica/alumina mole ratios above 40, preferably above l00, and most preferably above 300 can be prepared by the process of this invention.

[0024] The material of the present invention is prepared by mixing in water (preferably distilled or deionized) eth­ylenediamine, a boron oxide source, and the alcohol or aromatic compound. The order of addition is typically not critical and a typical procedure is to dissolve eth­ylenediamine and boric acid in water and then add the alcohol or aromatic compound. Generally, the silicon oxide compound is added with intensive mixing. The resulting slurry is transferred to a closed crystalliza­tion vessel for a suitable time. After crystallization, the resulting crystalline product can be filtered, washed with water, dried, and calcined.

[0025] During preparation, acidic conditions should be avoided. Advantageously, the pH of the reaction system falls within the range of about 8 to about l2 and most preferably between about 9 and about l0.5. The pH is controlled by the concentration of ethylenediamine.

[0026] In a more detailed description of a typical prepara­tion of this invention, suitable quantities of ethylene­diamine and boric acid (H₃BO₃) are dissolved in distilled or deionized water followed by addition of the aromatic compound or aliphatic alcohol. The resulting slurry is transferred to a closed crystallization vessel and reacted usually at a pressure at least the vapor pressure of water for a time sufficient to permit crystallization which usually is about 0.5 to about l00 days, typically is about 2 to about 20 days, and preferably is about 3 to about l4 days, at a temperature maintained below the decomposition temperature ranging from about l00° to about 200°C, preferably about l20° to about l80°C. The crystallizing material can be stirred or agitated as in a rocker bomb. Preferably, the crystallization temperature is maintained below the decomposition temperature of the alcohol or aromatic compound used in the preparation. Especially preferred conditions are crystallizing at about l65°C for about 2 to about l4 days. Samples of material can be removed during crystallization to check the degree of crystallization and determine the optimum crystallization time.

[0027] The crystalline material formed can be separated and recovered by well-known means such as filtration with washing. This material can be mildly dried for anywhere from a few hours to a few days at varying temperatures, typically about 25° to 200°C, to form a dry cake which can then be crushed to a powder or to small particles and extruded, pelletized, or made into forms suitable for its intended use. Typically, materials prepared after mild drying contain amounts of the alcohol or aromatic com­pound and water of hydration within the solid mass. A subsequent activation or calcination procedure is neces­sary, if it is desired to remove these material from the final product. Typically, mildly dried product is cal­cined at temperatures ranging from about 260° to about 850°C and preferably from about 525° to about 600°C. Extreme calcination temperatures or prolonged crystallization times can prove detrimental to the crystal structure or may totally destroy it. Generally, there is no need to raise the calcination temperature beyond about 600°C in order to remove organic material from the originally formed crystalline material. Typi­cally, the molecular sieve material is dried in a forced draft oven at about l45°-250°C for about l6 hours, then calcined in air in a manner such that the temperature rise does not exceed l25°C per hour until a temperature of about 540°C is reached. Calcination at this tempera­ture usually is continued for about 4 to l6 hours.

[0028] A catalytically active material can be placed onto the boronaaronate structure by ion exchange, impregna­tion, a combination thereof, or other suitable contact means. The cation, M, in the crystalline boronaaronate is usually hydrogen ion, but can be other cations including metal ions and their amine complexes, alkylam­monium ions, ammonium ions, and mixtures thereof by replacing the hydrogen ion, by ion exchange, with these cations. The cation has a valence, n, which can be l to 8, preferably l to 6, and most preferably l, 2 or 3. Preferred replacing cations are those which render the crystalline boronaaronate catalytically active, espe­cially for hydrocarbon conversion. Typical catalytically active ions include metal ions of Groups IB, IIA, IIB, IIIA, and VIII, and of manganese, vanadium, chromium, uranium, and rare earth elements. Water soluble salts of catalytically active materials can be impregnated onto the crystalline boronaaronate of this invention. Such catalytically active materials include hydrogen, metals of Groups IB, IIA, IIIA, IVB, VIB, VIIB, and VIII, and rare earth elements.

[0029] Ion exchange and impregnation techniques are well known in the art. Typically, an aqueous solution of a cationic species is exchanged one or more times at about 25° to about l00°C. Impregnation of a catalytically active compound on the boronaaronate or on a composition comprising the crystalline boronaaronate suspended in and distributed throughout a matrix of a support material, such as a porous refractory inorganic oxide such as alu­mina, often results in a suitable catalytic composition. A combination of ion exchange and impregnation can be used. The presence of sodium ion in a composition usu­ally is detrimental to catalytic activity. Catalyst com­positions useful in xylene isomerization can be based on hydrogen form sieves or on that prepared by ion exchange with species such as nickelous nitrate or by impregnation with species such as ammonium molybdate.

[0030] The amount of additional catalytically active material placed on the boronaaronate can vary from less than l wt. % to about 30 wt. %, typically from about 0.05 to about 25 wt. %, depending on the intended use. The optimum amount can be determined by routine experimenta­tion.

[0031] The crystalline boronaaronate useful in this inven­tion can be incorporated as a pure material in a catalyst or adsorbent, or may be admixed with or incorporated within various binders or matrix materials depending upon the intended process use. The crystalline boronaaronate can be combined with active or inactive materials, syn­thetic or naturally-occurring zeolites, as well as inor­ganic or organic materials which would be useful for binding the boronaaronate. Well-known materials include silica, silica-alumina, alumina, alumina sols, hydrated aluminas, clays such as bentonite or kaoline, or other binders well known in the art. Typically, the boronaaro­nate is incorporated within a matrix material by blending with a sol of the matrix material and gelling the resulting mixture. Also, solid particles of the boronaa­ronate and matrix material can be physically admixed. Typically, such boronaaronate compositions can be pelle­tized or extruded into useful shapes. The crystalline boronaaronate content can vary from anywhere up to l00 wt.% of the total composition. Catalytic compositions can contain about 0.l wt.% to about l00 wt.% crystalline boronaaronate and typically contain about 2 wt.% to about 65 wt.% of such material.

[0032] Catalytic compositions comprising the crystalline boronaaronate of this invention and a suitable matrix material can be formed by adding a finely-active metal compound to an aqueous sol or gel of the matrix material. The resulting mixture is thoroughly blended and gelled, typically by adding a material such as aqueous ammonia. The resulting gel can be dried and calcined to form a composition in which the crystalline boronaaronate and catalytically active metal compound are distributed throughout the matrix material.

[0033] The methods of catalyst formulation in a matrix which are described in U.S. Patent Nos. 4,268,420, 4,269,8l3, and European Published Application 68,796 (all incorporated by reference herein) can be used to prepare catalytic formulations incorporating boronaaronate.

[0034] The boronaaronates prepared according to this inven­tion are useful as catalysts for various hydrocarbon con­version processes and are suitable for chemical adsorp­tion. As used herein, the term hydrocarbon conversion means any changing or altering of the carbon bonding or structure of an organic compound containing at least carbon and hydrogen atoms. Included in hydrocarbon con­version processes are isomerization, oligomerization, polymerization, dehydration, dehydrogenation, alkylation, dealkylation, aromatization, hydrocracking, dewaxing, and the like. Some of the hydrocarbon conversion processes for which the boronaaronate appears to have useful cata­lytic properties are fluidized catalytic cracking; hydro­cracking; isomerization of normal paraffins and naphthenes; reforming of naphthas and gasoline-boiling-­range feedstocks; isomerization of alkylaromatics, such as xylenes; disproportionation of aromatics, such as toluene, to form mixtures of other more valuable products including benzene, xylene, and other higher methyl-sub­stituted benzenes, hydrotreating, alkylation, including (a) alkylation of benzenes with ethylene, ethanol, or another ethyl carbonation precursor to yield ethylben­zene, (b) alkylation of benzene or toluene with methanol or another methanol or carbonation precursor to yield xylene, especially p-xylene, or pseudocumene, (c) alkyla­tion of benzene with propylene and (d) alkylation of C₃ to C₅ paraffins with C₅ to C₃ olefins, hydrodealkylation; hydrodesulfurization; and hydrodenitrogenation. They are particularly suitable for the isomerization of alkylaro­matics, such as xylenes, and for the conversion of ethyl­benzene. Boronaaronate catalysts can be used to convert alcohols, such as methanol, to hydrocarbon products, such as aromatics or olefins.

[0035] Operating conditions for hydrocarbon conversion broadly comprise a temperature of about 95° to about 540°C., a hydrogen-to-hydrocarbon mole ratio of about 0 to about 20, a weight hourly space velocity (WHSV) of about 0.0l weight unit of feed per hour per weight unit of catalyst (hr⁻¹) to about 90 hr⁻¹, and a pressure of about 0.l atmosphere to about l00 atmospheres.

[0036] The boronaaronates prepared by this invention are especially suitable for hydrocarbon isomerization and disproportionation. They are especially useful for liquid- or vapor-phase isomerization of xylenes. In a preferred process, a boronaaronate-based catalyst con­ verts a hydrocarbon stream containing C₈ aromatics by isomerization of xylenes and concurrent conversion of ethylbenzene by hydrodealkylation and disproportionation mechanisms. Advantageously, the conditions for isomeri­zation of xylenes and conversion of ethylbenzene comprise a temperature of about 250° to about 480°C, a hydrogen-­to-hydrocarbon mole ratio of about l to about l2, a WHSV of about l hr⁻¹ to about 20 hr⁻¹, and a pressure of about l0 psig to about 500 psig. The preferred conditions for the isomerization of xylenes comprise a temperature of about 3l5° to about 455°C, a hydrogen-to-hydrocarbon mole ratio of about 2 to about 8, a WHSV of about l hr⁻¹ to about l0 hr⁻¹, and a pressure of about l00 psig to about 300 psig. The choice of catalytically active metals to be placed on the crystalline boronaaronate can be selected from any of those well known in the art. When used as a catalyst in isomerization processes with sui­table catalytically-active materials placed on boronaaro­nate, good selectivities for production of desired isomers are obtained.

[0037] When boronaaronate is used as a hydrocracking cata­lyst, hydrocracking charge stocks can pass over the cata­lyst at temperatures anywhere from about 260° to about 455°C or higher using known mole ratios of hydrocarbon to hydrogen and varying pressures anywhere from a few up to many thousands of pounds per square inch or higher. The weight hourly space velocity and other process parameters can be varied consistent with the well-known teachings of the art.

[0038] Boronaaronate is also suitable as a reforming cata­lyst to be used with the appropriate hydrogenation compo­nents at well-known reforming conditions including tem­peratures ranging from about 260° to 565°C or more, pressures anywhere from a few up to 300 psig to l,000 psig, and weight hourly space velocities and hydrogen-to-hydrocarbon mole ratios consistent with those well known in the art.

[0039] The boronaaronates of this invention can also be used as adsorbents to selectively absorb specific isomers or hydrocarbons, in general, from a liquid or vapor stream. For example, selective absorption of branched chain hydrocarbons from cyclic hydrocarbons is possible.

[0040] The following examples demonstrate, but are in no way intended to limit the present invention.

EXAMPLE l

[0041] Samples of crystalline boronaaronates according to this invention were prepared by dissolving 26.9 grams of boric acid, l03.4 grams of pyridine, and l40.9 grams eth­ylenediamine in 980.0 grams of distilled water in a labo­ratory stirrer. At this point the pH was measured and adjusted to about 9 with ethylenediamine. To this solu­tion, 5ll.9 grams of Ludox AS-40, an ammonia stabilized colloidal silica (40% solids), were added with vigorous stirring which continued for about l5 minutes after addi­tion. The resulting curdy, gelatinous mixture was placed in a stirred, sealed crystallization vessel and heated to l50°C for ten days. The resulting crystalline material was recovered by filtration and washed thoroughly with distilled water. The material was then dried for at least four hours at 329°F (l65°C), heated to l,000°F (538°C) over four hours and held at that temperature for twelve hours. The temperature was then reduced over four hours from l,000°F (538°C) to l20°F (49°C).

[0042] The X-ray powder diffraction measurements shown in the following tables were obtained on a Scintag PAD V instrument. Data were collected from 5 to 70 degrees two theta in 0.02 degree steps, with a counting time of 4 sec/step. The radition was Ni-filtered Cu K alpha. Slits on the incident beam were 2 and 4 degrees and slits on the diffracted beam were 0.5 and 0.3 degree. Peaks from K alpha 2 were removed using Scintag's software.

[0043] In reporting the results obtained, relative intensi­ties,i.e., relative peak heights, were arbitrarily assigned the following values:

These assigned strengths are used throughout this appli­cation. It is noted however that relative peak heights may vary from sample to sample and particularly from data taken on different instruments. Thus, an observed rela­tive peak height and corresponding assigned strength should be used as approximations in determining the structure of any particular crystalline material.

[0044] An X-ray diffraction spectrum of the preparation was measured and contained the lines specified in Table III.

[0045] The catalyst was prepared by dispersing the above calcined sieve in PHF-alumina which is initially an acetic acid stabilized alumina hydrosol containing about l0% Al₂O₃. Forty grams of calcined sieve were mixed with sufficient distilled water to fill sieve pores. The wet sieve was then added and thoroughly mixed in a high speed blender with 605 grams of the alumina hydrosol. The mix­ture was gelled (solidified) with the addition of 60 mil­liliters of concentrated (28 wt.%) aqueous ammonia. The resulting solid was dried for at least four hours at 329°F (l65°C), heated to l,000°F (538°C) over four hours, and held at that temperature for four hours. The temper­ature was then reduced over four hours from l,000°F (538°C) to l20°F (49°C). The calcined solid was crushed and sized to l8 to 40 mesh (U.S. Sieve Series).

EXAMPLES 2-4

[0046] Four additional samples of the crystalline boronaa­ronate molecular sieve were prepared in a manner similar to that described for Example l. All exhibited X-ray patterns contain lines corresponding to those shown in Table I. Details of these preparations are summarized in the following table:

[0047] The catalyst was prepared by dispersing the above calcined sieve in 756 grams of PHF-alumina which is ini­tially an acetic acid stabilized alumina hydrosol con­taining about l0% Al₂O₃. Distilled water (300 grams) was added to 50 grams of calcined sieve to fill sieve pores. The wet sieve was then added and thoroughly mixed with 756 grams of alumina hydrosol. The mixture was gelled by adding 60 milliliters of concentrated (28 wt.%) aqueous ammonia with stirring. The resulting solid was dried for l6 hours in a forced air oven at 200°C. The dried solid was calcined at 485°C for l2 hours. The calcined solid was crushed to l8/40 mesh (U.S. Sieve Series). Fifteen grams of the l8/40 mesh catalyst were placed in a micro aromatics test unit and preconditioned for two hours at the reactor temperature and pressure at the WCF per hour of hydrogen designated in Tables V and VI. The xylene isomerization test results are summarized in Tables V and VI.

EXAMPLE 6

[0048] Ninety-three grams of boric acid, l6l grams of eth­ylenediamine and 200 grams of isopropyl alcohol were mixed in 700 grams of water. The mixture was homogenized at maximum speed then 500 grams of Nalco 2327 (40% solids) were added and the mixture was homogenized for 5 minutes at maximum speed. The resulting mixture was placed in a stirred, sealed crystallization vessel and heated to l65°C for 4 days. The resulting crystalline material was recovered by filtration, washed thoroughly with distilled water, and dried in a forced draft oven at 200°C for l6 hours. The catalyst was prepared according to the procedure described in Example 2.

[0049] An example of the X-ray diffraction pattern for the boronaaronate after calcination at 537°C is presented in Table VII:

EXAMPLES 7-9

[0050] Four additional samples of the crystalline boronaa­ronate molecular sieve were prepared in a manner similar to that described in Example 6. All exhibited X-ray pat­terns containing lines corresponding to those shown in Table I. Details of these preparations are summarized in Table VIII.

[0051] Catalyst compositions were prepared from these samples and tested in xylene isomerization using procedures similar to those described in Example l. Results of these tests are summarized in the following tables:

Claims

1. A crystalline molecular sieve identified as boronaaronate having a composition in terms of mole ratios of oxides:
    0.9±0.2M_2/nO:B₂O₃:ySiO₂:zH₂O
wherein M is a cation of valence n, y is above 2 and z is between 0 and about 200 and having an X-ray diffraction pattern substantially as shown in Table I.

2. The molecular sieve of claim l wherein M is hydrogen.

3. The molecular sieve of claim l or claim 2 wherein y is between about 5 and about l50.

4. The molecular sieve of any preceding claim which further contains Al₂O₃ wherein the SiO₂/Al₂O₃ mole ratio is above about 300.

5. A composition comprising the boronaaronate of any preceding claim wherein said boronaaronate is incorporated within a suitable matrix material.

6. The composition of claim 5 wherein said matrix material comprises silica, silica-alumina, or alumina.

7. A method for preparing a crystalline molecular sieve composition having in terms of mole ratios of oxides:
    0.9±0.2M_2/nO:B₂O₃:ySiO₂:zH₂O
wherein M is a cation of valence n, y is between 2 and about 700, and z is between 0 and about 200 and having the X-ray diffraction pattern substantially as shown in Table I which method comprises reacting under crystalli­zation conditions an aqueous mixture containing an oxide of boron, ethylenediamine, an oxide of silicon, and an organic material comprised of a heterocyclic aromatic compound or an aliphatic alcohol or a combination thereof in the substantial absence of alkali or alkaline earth metal ions wherein said aromatic compound contains about 4 to about 9 carbon atoms and at least one nitrogen atom in the aromatic nucleus.

8. The method of claim 7 wherein the crystallizing mixture is maintained at about l00°C to about 200°C for about 2 to about 20 days.

9. The method of claim 7 or claim 8 wherein said organic material comprises a heterocyclic nitrogen-containing aromatic compound and the mole ratio of said compound to silica is between about 0.2 and about 3.0, the mole ratio of silica to oxide of boron is between about 5 and about l50, and the mole ratio of water to silica is between about l5 and about 80.

l0. The method of claim 9 wherein the mole ratio of said compound to silica is between about 0.3 and about 2.0, the mole ratio of silica to oxide of boron is between about l5 and about 50, and the mole ratio of water to silica is between about 20 and about 40.

11. The method of any of claims 7 to l0 wherein said hetero­cyclic nitrogen-containing aromatic compound is selected from pyridine, its aryl- or alkyl-substituted deriva­tives, quinoline, or isoquinoline.

12. The method of claim 7 or claim 8 wherein said organic material comprises an aliphatic alcohol and the mole ratio of said alcohol to silica is between about 0.4 and about 4.0, the mole ratio of silica to oxide of boron is between about 5 and about l50, and the mole ratio of water to silica is between about l5 and about 80.

13. The method of any of claims 7 to l0 wherein said compound comprises quinoline or isoquinoline.

14. The method of any of claims 7 to l2 wherein said alcohol contains l to l0 carbon atoms.

15. A hydrocarbon conversion process which com­prises contacting a stream containing organic compounds at conversion conditions with a catalytic composition comprising crystalline boronaaronate having the following composition in terms of mole ratios of oxides:
    0.9±0.2M_2/nO:B₂O₃:ySiO₂:zH₂O
wherein M is a cation of valence n, y is between 2 and about 700, and z is between 0 and about 200 and having the X-ray diffraction pattern substantially as shown in Table I.

16. The process of claim l5 wherein said crystalline boronaaronite is as defined in any of claims 2 to 6, and/or is produced by the method of any of claims 7 to l4.

17. The process of claim l5 wherein said conver­sion conditions comprise a temperature of about 95°C to about 540°C, a hydrogen-to-hydrocarbon ratio of about 0 to about 20, a weight hourly space velocity (WHSV) of about 0.0l weight unit of feed per hour per weight unit of catalyst (hr⁻¹) to about 90 hr⁻¹, and a pressure of about 0.l atm to about l00 atms.

18. A process according to claim l5 or claim l6 for the isomerization of xylene wherein said stream comprises a xylene feed, which process comprises contacting said feed at isomerization conditions with said catalytic composition.

19. The process of claim l8 wherein said isomeri­zation conditions comprise a temperature of about 250°C to about 480°C, a hydrogen-to-hydrocarbon ratio of about l to about l2, a weight hourly space velocity (WHSV) of about l weight unit of feed per hour per weight unit of catalyst (hr⁻¹) to about l2 hr⁻¹ , and a pressure of about l0 psig to about 500 psig.